I've had some reject my e-mail address because it contains their company name. REI was one (ie it wouldn't allow [email protected] but would accept [email protected])
I was just able to create an account using `rei@<mydomain>` on rei.com w/o any issues. Now, figuring out how to delete the account is another matter entirely...
Should have registered as rei-are-incompetent-idiots@ instead…
I haven't had an outright rejection, but definitely a few odd moments with call center agents. "[email protected]" is definitely not the default expectation :)
I had my account marked as suspicious and closed in a financial institution for this a few years ago. They were concerned I was a bad actor attempting to impersonate an employee. It was very annoying, because no one from customer support could talk to me directly, it had to flow through legal. Very stupid.
I have since stopped doing this out of fear that it will actually cause me more headaches with people/systems that don't understand how email works.